Coffee machine

ABSTRACT

A coffee machine is provided having a housing containing removable first and second modules. The first module includes removably connected first and second submodules. The first submodule includes a brewing device. The second submodule includes a motor, a driving axle, gears for coupling the driving axle to the motor, and a further housing enclosing the motor and gears such that the driving axle extends through the housing and establishes a functional connection with said brewing device. The operational ability of the first module, when removed from the housing, can be checked because the means for supplying driving energy to the motor remains connected to the motor. For cleaning, the first submodule can be removed from the second submodule once electrical and liquid lines have been disconnected. The second module includes a fresh water container, a coffee grounds container, a residual water container, and control and heating elements for supplying fresh water from the fresh water container to the brewing device. Thanks to this modular design, cleaning, servicing, repairing and checking tasks may be easily carried out.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a coffee machine with a housing,control and heating elements to heat up and supply fresh water to abrewing device, which comprises a brewing cylinder and two pistons, thebrewing cylinder being drivable with a motor via a drive spindle andmoveable in relation to the pistons.

2. Description of the Related

To prepare coffee with automatic coffee machines the so-called pressurebrewing process is often used today. With this process hot water isconveyed under pressure through coffee powder present in a brewingchamber. The present invention relates in particular to coffee machinesworking according to this pressure brewing process. Many of them arealready well-known on the market. Depending upon area of application,for example in households or in restaurant businesses, these knowncoffee machines differ in their construction especially with respect torobustness, flexibility in the running of the process, ease inservicing, cleaning and maintenance.

It is of common knowledge that in all coffee machines working accordingto the pressure brewing process, parts which come into contact withcoffee powder and/or with the prepared drink are subjected to a certainsoiling and have to be cleaned periodically. The cleaning of such partsvaries in expense and time intensity from machine type to machine type.Depending upon the construction of a machine, the design of individualparts is more or less complicated with respect to maintenance orrepairs.

In the German unexamined and published patent application DE 29 45 360,an automatic coffee machine is disclosed which works according to thepressure brewing process in which maintenance is facilitated in that theimportant elements of the coffee machine are housed in a kind of drawerwhich can be pulled out of the latter. In the housing of the coffeemachine itself only a water tank and an outlet to provide the electricalconnection between housing and drawer remain as securely installedelements. It follows from the specification of the German publishedapplication in connection with the drawings that, among other things,electrical, electromechanical as well as purely mechanical parts arehoused in the drawer or in the module. One can say that the drawercontains all important elements and components of the coffee machine.These elements and components will be more easily accessible, especiallyfor maintenance and repairs, than other embodiments of these types ofcoffee machines. For the periodic cleaning of the coffee-carryingelements, however, the brewing device as a component, for example, hasto be to be dismounted or removed from the drawer each time, in thatfirst the electrical and hydraulic connecting lines are disconnected andafterwards the brewing device itself removed by unscrewing theattachment screws. Such a procedure is disadvantageous for a processwhich is to be carried out periodically. Furthermore in the drawer thereis a high risk of electrification due to the common arrangement of partscarrying electrical current and parts coming into contact with water.

In the European patent specification EP 0 154 206, a device is disclosedfor preparation of hot drinks, especially coffee, in which a subassemblyholder, removable from the device, is foreseen comprising all the partsexposed to soiling from coffee powder or from the prepared drink. Thisfacilitates handling when cleaning the device in that only thesubassembly holder has to be taken from the device. Since all the otherparts are mounted securely in the coffee machine, a decisive advantagefor cleaning purposes can no doubt be achieved through the designchosen, but not for servicing and repairs, however. Design of the otherparts may not be necessarily easy. A control of the function of thecoffee machine is only possible with the subassembly holder integratedor installed.

SUMMARY OF THE INVENTION

The object of the present invention is to create a coffee machine whichpermits comfortable cleaning of the parts subjected to soiling fromcoffee powder and/or from the prepared drink, permits a simple controlof the efficiency, and which is designed of favorable construction forreplacing individual parts when carrying out maintenance and servicingfor repairs.

This object is fulfilled with a coffee machine which is characterized inthat at least a first module divisible into two submodules is provided,the first submodule comprising a brewing device and in the secondsubmodule there being disposed at least a driving motor or electromotorand gears, and in that the first module is detachable from the coffeemachine in such a way that in the detached state the brewing device cancontinue to be driven by the motor.

The coffee machine according to the invention has a modularconstruction. The first module detachable from the machine isconstructed of two separable submodules. The first submodule comprisesthe brewing device with the parts subjected to soiling from coffeepowder and/or from the prepared drink. In the second submodule thedriving motor is housed with the gear in a housing essentiallysplashproof. A plug connection, which is disposed on the housing of thesecond submodule, is provided for conducting electricity to the drivingmotor, an electromotor. After detachment of the first module from thecoffee machine, the functioning of the brewing device can be examined atany time for servicing and repair purposes. The two submodules can beseparated from each other for cleaning of the soiled parts of thebrewing device. The brewing device can then be rinsed under a stream ofwater without the danger arising thereby that electrical orelectromechanical parts become wet.

It is particularly advantageous if the remaining parts of the coffeemachine are combined into further, easily detachable modules.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention is more closely described in thefollowing description and drawings, wherein:

FIG. 1 is a profile of the coffee machine, the side part of the housingfacing the viewer having been removed;

FIG. 2 is a front view of the machine with the first module pulled out;

FIG. 3 is a front view of the first module removed from the coffeemachine divided into two submodules; and

FIG. 4 is a schematic view of control and heating elements for thecoffee machine according to the invention combined into a furthermodule.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The coffee machine shown in FIGS. 1 and 2 comprises a housing 1.Contained in this housing are a fresh water receptacle 2, a receptaclefor coffee grounds 3 and a residual water receptacle 4. Thefirst-mentioned receptacle can be filled and refilled through a freshwater feed opening 40, which is disposed on the top of the housing. Amill work 5, whose coffee bean container projects out of the housing, isalso included. The machine has further control and heating elements,which are designated together under the reference symbol 6 in thesefigures. Detailed data on the individual elements is given further back.A control plate 7, preferably a printed card with electronic componentsinserted, is provided as the control unit for control of the coffeemachine. A brewing unit or device 8 comprises a brewing cylinder 9, anupper or first piston 10, a lower or second piston 11 as well as drivespindle 12 rotatable around its longitudinal axis, the outer surfacearea of which is provided with a trapezoidal thread. The drive spindle12 is positioned so that it can turn on both ends. The brewing cylinder9 has a formation on its side facing the drive spindle 12 which mesheswith the thread of the drive spindle. Through the turning of the latterthe brewing cyclinder 9 moves, depending upon the direction of rotation,up in the direction of the upper piston 10 or down. In its upwardsmovement the brewing cylinder 9 essentially drags along the lower piston11. The position of the brewing device 8 presented in FIG. 1 is theso-called feed position. The coffee ground by the mill work 5 reachesthe brewing cylinder 9 in powder form via a coffee feed device 13.Following the feed step, the brewing cylinder 9, driven by the drivespindle 12, is guided upwards over the upper piston 10, the brewingcylinder 9 forming a brewing chamber. Through a first liquid pipe 29 anda first connection nipple 34, hot water under pressure reaches thebrewing chamber which has been formed. After the coffee powder hasflowed through, the water leaves the brewing chamber via a secondconnection nipple 35, to which a second liquid pipe 30 is connected. Theend of said liquid pipe facing away from the second connection nipple 35empties into a drink dispensing nozzle 36, through which the freshlybrewed coffee flows into a cup placed below it. At the end of thebrewing process, the brewing cylinder 9 is moved downwards in theopposite direction through rotation of the drive spindle 12, the lowerpiston 11 gradually reaching the vicinity of the upper edge of thebrewing cylinder 9 by means of friction elements which are not portrayedin the figures. The leached coffee powder lies on the surface of thelower piston 11, and can be pulled off by a discharge device 14 andconveyed into the receptacle for coffee grounds. Through partial upwardmovement of the brewing cylinder 9, the feed position presented in FIG.1 is reached again, the lower piston 11 being hindered from movingupward for the time being by the aforementioned friction elements whichare not illustrated.

The aforementioned parts of the brewing device 8 are disposed between afirst and a second side wall 37, 38. For the sake of clarity, the secondside wall 38 has been omitted in FIG. 1. The brewing device 8 comprisesall those parts which come into contact with the coffee powder and/orthe prepared drink and are thereby subjected to soiling. All these partsare made preferably of plastic, and thus are not subjected to anycorrosion.

The lower end of the drive spindle 12 extends over a drive axle 20,which projects out of a further housing 19 through an opening with asealing means 22, for example an O-ring. Housed in the further housing19 are a motor 15, preferably an electromotor, to which gears 18 arecoupled. The aforementioned drive axle 20 extends from the gears throughthe said sealed opening into the area of the lower end of the drivespindle 12. Enclosed by the further housing 19, the electromotor 15 isprotected against splashing water.

In the coffee machine according to the invention a first module isformed, which consists of a first submodule and a second submodule 17.The first submodule having the brewing device 8 and the second submodulehaving essentially the motor 15, the gears 18 with the axle 20 and thefurther housing 19 that encloses these components. A slide rail 26extending away from the housing is disposed on each of two oppositesides of the further housing 19. Each of these slide rails grip in guiderails 25, which are formed on the housing 1 of the machine in such a waythat it is possible for the first module 16 to be pulled out of thecoffee machine. The pulled out position of this first module is shown inFIG. 2. A first housing side part 39 of the housing 1 can, for example,be fixed on the further housing 19 of the second submodule 17. Inpulling the first module 16 out of the coffee machine, the side part 39opens up the housing 1 and, at the same time, makes the parts remaininginside accessible. It is thereby self-evident that the first and thesecond liquid pipes 29, 30 are each designed in such a length that thepulling out of the first module 16 is not hindered. On the furtherhousing 19 a plug connection 21 is foreseen through which the necessarydriving energy is supplied to the motor 15 via electrical connectionsnot portrayed in the figures. It is thereby possible for the brewingdevice 8 to be operated and its efficiency checked even when the firstmodule is in a pulled out state. This is an important advantage formaintenance and repair, as already mentioned above.

It follows moreover from FIG. 2 that the first liquid pipe 29 reachesfrom said first connection nipple 34 to a connection 51, which isdisposed in a further submodule 6, in which the control and heatingelements are combined. A fresh water pipe 53 extends from the lower endof the fresh water receptacle 2 to a fresh water connection 50 of thefurther submodule 6. A residual water pipe 52 projects from a residualwater connection 49 of the further submodule 6 into the residual waterreceptacle 4.

An especially advantageous construction of the coffee machine results inthat the fresh water receptacle 2, the coffee grounds receptacle 3 andthe residual water receptacle 4 are combined into a second module 33.Like the first module 16, the second module 33 can be pulled out of thecoffee machine, and moreover, can be pulled out together with the secondhousing side part 54, on the side of the coffee machine facing away fromthe first housing side part. It is particularly advantageous if thefurther submodule 6 is a removable part of the second module 33.

The two liquid pipes 29, 30 are disposed attachably to, and detachablyfrom, the first and second connection nipples 34, 35 of the brewingdevice 8 via first and second coupling means 31, 32, for exampleconnecting clips. After severance of the liquid pipes 29, 30 from thebrewing device 8 and the separation of the electrical line, not shown,from the plug connection 21, the first module 16 can be completelyremoved from the coffee machine, as shown in FIG. 3. The firstsubmodule, essentially the brewing device 8, is held by spring clips 41which are fixed to the further housing 19 of the second submodule 17,and which grip into correspondingly disposed grooves 42 in the two sidewalls 37, 38 of the brewing device 8. The brewing device 8 can beseparated from the second submodule 17 through a sideways unfastening ofthe spring clips 41 out of the grooves 42. Thus it becomes visible thatthe end area of the drive axle 20 facing the drive spindle 12 isequipped with first drive means 23, for example an external toothedwork, which drive means are meshed with second drive means 24 when thebrewing device 8 is put on, for example an internal toothed work of thelower end area of the hollow-constructed drive spindle. Separated fromthe second submodule 17, the first submodule 8, which comprises, asalready mentioned, all the parts subjected to soiling from coffee powderand/or coffee, can be rinsed off and cleaned easily under a stream ofwater in this way without the danger arising of some electricalcomponent or other becoming wet. It is important to realize that nodisassembly procedures, such as untightening of screws, are necessary asis the case with other machines. Every housewife will be able to carryout these periodically necessary cleaning steps.

In a similarly easy way the previously mentioned receptacles 2, 3, 4 canbe cleaned by pulling out the second module 33. Should the furthersubmodule 6 and the control plate 7 also be parts of the second module33, it is recommended that these two parts be disposed in waterproofhousings and that a possibility of separation be foreseen, for exampleby means of a catch or snap device.

For the sake of completeness, the control and heating elements of thecoffee machine have been symbolically portrayed, combined into a furthersubmodule 6, in FIG. 4. Passing through a water apportioning element 45,fresh water from the fresh water supply 50 reaches the water heatingelement 46 by means of a fresh water pump 43, which is driven by a freshwater pump motor 44. The heated water leaves the heating element andreaches connection 51 for the first liquid pipe 29 through brewing valve47. To avoid subsequent dripping of the drink dispensing nozzle 36, anyremaining water can flow off into the residual water receptacle throughconnection 49 for the residual water pipe after closing of theelectrically controlled brewing valve 47. When the pressure is too high,an overpressure valve 48 opens so that the hot water can reach theresidual water receptacle directly.

What is claimed is:
 1. Coffee machine comprising a housing (1), abrewing device having a brewing cylinder (9), two pistons (10, 11)closing said brewing cylinder to form a brewing chamber, and a drivingspindle (12) upon which said brewing cylinder is operably connected andmovable relative to the pistons, said coffee machine further comprisinga motor to drive said driving spindle, gears coupling said motor to saiddriving spindle, a first module (16) having first and second submodules(8, 17) and means for removably connecting said first and secondsubmodules, wherein said brewing device is disposed in said firstsubmodule and said motor (15) and said gears (18) are disposed in saidsecond submodule, and means for removably retaining said first module insaid housing, wherein said brewing device (8) continues to be operablewhen said first module is removed from said housing.
 2. Coffee machineaccording to claim 1 wherein said second submodule (17) has a furtherhousing (19) which encloses and contains the motor (15) and the gears(18) to protect the motor and gears from splashing water, and an axle(20) connected to the gears and having an end portion projecting out ofthe further housing (19) for coupling said gears to said drivingspindle.
 3. Coffee machine according to claim 2, wherein said secondmodule has sealing means (22) provided at a point of passage of the axle(20) through the further housing (19) of the second submodule (17). 4.Coffee machine according to claim 2, wherein said end portion of theaxle (20), projecting out of the further housing (19) of the secondsubmodule (17), is provided with first driving means (24), and saiddriving spindle is provided with second driving means (24) detachablyengaged to said first driving means.
 5. Coffee machine according toclaim 2, wherein said means for removably retaining said first module insaid housing Comprises guide rails (25) formed on the housing (1) andsliding rails (26) formed by the further housing (19) of the secondsubmodule (17), wherein said sliding rails engage said guide rails toslidably retain said first module in such a way that the first module(16) can be pulled out of the housing.
 6. Coffee machine according toclaim 1, further comprising means for supplying driving energy disposedin said housing and connected to said motor, and wherein said secondsubmodule (17) has a plug connection (21) for removably connecting saidmeans for supplying driving energy to the motor.
 7. Coffee machineaccording to claim 1, wherein said brewing device (8) has a coffee feeddevice for feeding coffee powder into said brewing cylinder, a dischargedevice for removing leached coffee powder, and two side walls betweenwhich the brewing device is disposed, said brewing device beingsubjected to soiling from the coffee powder and from prepared drink. 8.Coffee machine according to claim 1, further comprising liquid pipes(29, 30) for supplying water to said brewing device and removingprepared drink from said brewing device (8) and having coupling means(31, 32) provided on ends of said liquid pipes to detachably connect theliquid pipes (29, 30) to the brewing device (8).
 9. Coffee machineaccording to claim 1, further comprising a fresh water receptacleconnected to said brewing device for holding fresh water, a coffeegrounds receptacle disposed in said housing for receiving leached coffeepowder from said brewing device, a residual water receptacle connectedto said brewing device for holding residual water, a second module (33),wherein said fresh water receptacle (2), said coffee grounds receptacle(3) and said residual water receptacle (4) are disposed in said secondmodule, and means for removably retaining said second module in saidhousing.
 10. Coffee machine according to claim 9, further comprisingcontrol and heating elements connected between said fresh waterreceptacle and said brewing device for heating said fresh water andsupplying said fresh water to said brewing device, and wherein saidsecond module (33) has a further submodule (6) in which said control andheating elements are disposed.